This invention relates generally to proportioner devices for mixing liquids in predetermined relative proportions and more particularly to a liquid proportioning system adapted for quick change of the relative mixing proportion of the liquids.
Liquid proportioner devices of the type to which the present invention relates are particularly applicable in the dilution of a concentrated liquid chemical, such as a detergent, in water prior to use. Such devices are commonly used in building maintenance applications for mixing concentrated cleaning chemicals. Previously, to change the relative mixing proportion (dilution ratio) of the concentrate with water the user had to replace a relatively small metering tip in the liquid chemical flow line which controlled the flow rate of the liquid chemical into a mixing chamber. Disassembly of the proportioner device and manipulation of the metering tips is a slow, cumbersome process. In order to assure the proper dilution ratio, a chart has to be read which relates the particular liquid chemical being diluted to the specific metering tip to be employed. The flow line is often semi-permanently attached so that it is difficult to remove from the liquid proportioner device. The small size of the metering tips makes them extremely difficult to handle, and easy to lose in a janitor's closet crowded with equipment.
With the present liquid proportioning devices, a user may easily select the wrong device by misreading the chart or simply forgetting to change the metering tip which is unseen unless the device is disassembled. The user may also intentionally not follow the recommended dilution of the detergent out of the view that if a little is good, a lot is better. Selection of the proper dilution ratio cannot be overemphasized where detergents are involved. If the dilution ratio is too high in detergent, the item to be cleaned can be damaged.
The same problems described above associated with selecting and changing the metering tip arise when a different chemical is to be diluted with the same liquid proportioner device. A different chemical usually requires a different dilution for use. In addition, different chemicals have different flow characteristics requiring different metering tips to produce the same dilution ratio.
Presently, some liquid proportioning systems are available which provide variable dilution ratios of a concentrated liquid chemical and/or multiple concentrated liquid chemicals without manipulation of the metering tips. However, these systems consist of a plurality of individual liquid proportioning devices and metering tips, one for each chemical and/or dilution ratio. Such systems provide a fixed number of dilution ratios for a fixed number of liquid additives. Any change from the preset configuration will require changing the metering tips. Additionally, such systems are prohibitively expensive for most applications.
Therefore, there is presently a need for a liquid proportioning system having a simple and yet inexpensive mechanism for changing the liquid chemical or the dilution ratio of the liquid chemical.